SEOUL , South Korea -LRB- CNN -RRB- -- A 69-year-old who was previously convicted of torching a palace has been arrested in connection with a fire that destroyed Namdaemun , South Korea 's oldest wooden structure and a national treasure , authorities said on Tuesday .

People on Monday look at the debris of the Namdaemun gate in central Seoul after the fire .

Similarities between the Sunday night fire and the 2006 blaze led to the investigation of a man identified only as Mr. Chae , said Kim Young-Su , chief of police of the Namdaemun police station . Chae had served time in prison for the palace fire .

Police searched the home of Chae 's ex-wife and found a can of paint thinner and a pair of leather gloves they believe were used in the fire , Kim said .

Chae confessed to starting the fire , saying he was upset by a land grievance that led him to start the 2006 fire and by the sentence he was handed in that case , Kim said .

Chae was free on a suspended sentence , Kim added .

Chae said he chose Namdaemun because it was easily accessible by public transportation and yet situated in a lightly populated area where the fire was unlikely to hurt people , according to police .

The fire burned for hours , and more than a hundred firefighters tried to save it . Watch the reaction to the Namdaemun 's destruction ''

Namdaemun was more than 600 years old and stood at the center of Seoul , having served as a main gate into the capital for centuries . The gate was considered a national symbol to Koreans around the world . E-mail to a friend

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NEW : `` Mr. Chae '' was convicted of torching a Korean palace in 2006

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NEW : Chae has confessed to starting the Namdaemun fire , police chief says

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NEW : Easy access , lightly populated area dictated Namdaemun choice , police say

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The more-than-600-year-old Namdaemun was country 's oldest wooden structure